CONFIG_CPU_SUBTYPE_SH7708 is not available for thedefaultarchitecture x86.
Result is shown for architecture sh
SH7708
modulename: setup-sh770x.ko
configname: CONFIG_CPU_SUBTYPE_SH7708
Processor subtype
└─>SH7708
In linux kernel since version 2.6.12
Select SH7708 if you have a 60 Mhz SH-3 HD6417708S or
if you have a 100 Mhz SH-3 HD6417708R CPU.
if you have a 100 Mhz SH-3 HD6417708R CPU.